When installing PEX tubing would there be any benefit in putting 2 pinch clamps over each nipple instead of 1 to prevent leaks? I am not concerned about the cost, as I bought more than 2x the clamps I need as a wholesale lot at a huge discount.


I will be installing Vitasalus whole house filtration system in my parents house after using the same system in my house for a couple of years. My install has been done by a plumber who used copper rings and initially about every other connection leaked, then all but one stopped. The remaining one leaks ever so slightly as to not warrant a call. This time I am doing work myself and using SS clamps.

  • Where is your house and your parents house? Are you putting in a new plumbing system for potable water throughout the house? How are you currently inspecting the joints in your system? May 17, 2017 at 19:04
  • One of the advantages of PEX is that you can often avoid having any fittings at all in inaccessible locations, which means they can all be inspected later on and repaired if ever needed. In some cases that might be impossible, like where a sharp 90 is needed; it might be advisable to install an access door (readily available specifically for this reason) in those spots. Mar 10, 2018 at 11:08

1 Answer 1


I assume you mean two crimp clamp rings one after the other (i.e., side by side) and not one on top of the other. Putting on two clamps might trap water between the two clamps. Mold and bacteria could grow in this space. This volume would not be swept by flow and would probably be anaerobic.

Unless doubling up on the clamps is a described optional 'heavy duty' installation method, this kind of installation would be contrary to the instructions/specifications for the system. It could fail inspection.

If you wanted to do something which would improve the quality of the system, I think a much better approach would be to implement a system where each clamp connection could be inspected with the house finished walls in place. This might be small ports with inconspicuous covers. They could be so small that a borescope might be required.

  • I do not see how 2 clamps on a 3/4" PEX nipple could trap water any more than 1 clamp would. This is still a dead end between the PEX pipe and a brass or plastic fitting, except that with 2 clamps it would be about 1/2" less deep.
    – ajeh
    May 17, 2017 at 20:29
  • 2
    The fittings look like they are just long enough to put on one crimp clamp, if it is put in the optimum position. You want some PEX extending past the clamp. If you do that, there might not be enough room for another clamp. A clamp near the end of the fitting might deform it or cause a failure of the PEX tubing. Unless you can find that others have successfully 'double-clamped' you are taking a risk of creating an unexpected problem. youtube.com/watch?v=q8J1yHRuFWs May 17, 2017 at 21:49
  • Got it, the length of the nipple is a good enough reason to stick with 1 clamp per connection. Thx!
    – ajeh
    May 18, 2017 at 14:27

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